Appliance devices such as dishwashers, clothing washing machines, dryers, ovens, refrigerators and the like often include electrical control circuits. Such control circuits receive input from the user and control the operation of the appliance device based on the received input. In many cases, the overall operation of the appliance is predefined as a general matter and the user input merely modifies the predefined operation in some way.
For example, the operation of a dishwasher typically involves the processes of filling, washing, draining and rinsing. Such operations involve, among other things, the control of water valves, detergent valves and motor relays. The general sequence of such operations is generally predefined. However, user input may be used to alter the sequence, or to define certain parameters of the sequence. For example, the user input operations is generally predefined. However, user input may be used to alter the sequence, or to define certain parameters of the sequence. For example, the user input may define whether the wash cycle is normal, light, or heavy. Although the general sequence does not necessarily change dependent upon wash cycle selection, the length of certain processes within the sequence does change.
A typical user input interface for a dishwasher includes a rotary knob and a plurality of pushbutton switches. The rotary knob is attached to a cam that controls the sequence of operations within the dishwasher. The cam has a number of followers that trigger the operation of the various dishwasher components. The cam followers are positioned to cause various operations to be executed in a “programmed” sequence. The user selects a particular cycle by rotating the knob to particular position associated with the selected cycle. Upon actuation, the cam begins to rotate automatically started from the user selected position, performing each operation as defined on the cam “program” from the user-selected point forward. The pushbutton switches are used to activate/deactivate various options that are not available through the cam program. For example, pushbutton switches may be used to selectively activate a heated dry cycle, a delayed start, or a high temperature wash.
More recently, electronic controllers, for example, microprocessors and microcontrollers, have replaced the rotary cam control device. The use of electronic controllers provides flexibility and features not typically available in cam control devices. Moreover, as a general matter, replacement of moving parts, such as electromechanical rotating cams, typically increases reliability in products.
However, the use of electronic controllers has added to the complexity of servicing appliances. Small electronic integrated circuits do not lend themselves to the methods of troubleshooting and repair that have historically been used with mechanical and electromechanical devices. Accordingly, malfunctions in an electronically controlled appliance are more difficult to diagnose and resolve than those of the old, mechanical cam controlled devices.
Some have proposed the incorporation of infrared and radio communication devices in appliances having microprocessors for the purpose of communicating troubleshooting data. However, infrared and radio communication modules add appreciable expense to the manufacture of appliances. Because appliance manufacturers operate with relatively low profit margins, an increase of even one dollar in cost is multiplied by the production output, which may be in the millions of units. Thus, the additional expense of long range communication modules, such as infrared and radio communication devices, may significantly impact the bottom line of an appliance manufacturer.
There is a need for incorporating communication in an appliance without significantly increasing the costs of manufacturing an appliance.
There is a need, therefore, for facilitating troubleshooting and repair of electronically controlled appliances.